Make sure you get an SSD that has its own garbage collection since TRIM isn't supported in XP, and probably isn't supported on your laptops chipset. The SSDs you listed should all work just fine, just be aware that you'll be limited to 150MB/s reads & writes.

TRIM is a function of the chipset? I was not aware of this. Given the age of the P770, I would not expect it to support TRIM in that case....the P770 uses the Mobile Intel QS57 Express chipset. Guess I need to do a bit more research......

Drop in speed is unavoidable, given the SATA1 interface. I was more concerned with compatibility and reliability and low power drain than speed....the upside is that I don't need to buy the latest and greatest and fastest SSD, since the laptop will never see the extra speed!